Taonia atomaria (Woodward) J. Agardh
Description: Thallus flat and leaf-like, to 300 mm long (usually 100-150 mm) and 10-40 mm broad; fronds thin and translucent, olive to yellow-brown, irrregularly forked-lacinate, lacking a midrib; reproductive structures characteristically formed in wavy bands.
Habitat: sunny, sandy pools in the lower intertidal in summer. Relatively rare.
Distribution: Widely distributed but onlylocally common in western Ireland and south-western Britain, south to Senegal; widespread in the Mediterranean.
Key characteristics: Absence of midrib, lacinate forking, reproductive structures in bands.